Cyclophosphamide increases transgene expression mediated by an oncolytic adenovirus in glioma-bearing mice monitored by bioluminescence imaging
Cyclophosphamide increases transgene expression mediated by an oncolytic adenovirus in glioma-bearing mice monitored by bioluminescence imaging
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DOI：
10.1016/j.ymthe.2006.08.008
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发表时间：
2006-12-01
影响因子：
12.4
通讯作者：
Chiocca, E. Antonio
中科院分区：
文献类型：
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作者：
Lamfers, Martine L. M.;Fulci, Giulia;Chiocca, E. Antonio
提高具有复制能力的腺病毒的溶瘤效能的方法包括将治疗性转基因插入病毒基因组。被这种“武装”病毒感染的细胞体内转基因表达的水平和持续时间知之甚少。使用肿瘤选择性腺病毒编码萤火虫荧光素酶（AdA24CMV-Luc），我们在颅内小鼠恶性胶质瘤模型中研究了这些问题。采用生物发光显像法检测荧光素酶的表达，并评价免疫抑制剂环磷酰胺（cyclophosphamide， CPA）对转基因表达的影响。肿瘤内注射AdA24CMV-Luc导致荧光素酶的局部剂量依赖性表达。令人惊讶的是，在14天的过程中，这种表达迅速下降。相比之下，注射了非复制性Ad的小鼠。CMV-Luc表达稳定。用CPA联合AdA24CMV-Luc治疗小鼠可以延缓转基因表达的丧失。小鼠脑内炎症细胞染色显示，经cpa处理的小鼠免疫细胞肿瘤浸润减少。此外，在免疫缺陷的NOD/SCID小鼠中，转基因表达的丧失速度较慢，CPA治疗不能阻止转基因表达的丧失。总之，我们的数据表明，在小鼠脑内瘤内注射溶瘤腺病毒后，转基因表达和病毒复制迅速下降，免疫调节剂CPA治疗延长了病毒介导的基因表达。
Approaches to improve the oncolytic potency of replication-competent adenoviruses include the insertion of therapeutic transgenes into the viral genome. Little is known about the levels and duration of in vivo transgene expression by cells infected with such "armed" viruses. Using a tumor-selective adenovirus encoding firefly luciferase (AdA24CMV-Luc) we investigated these questions in an intracranial mouse model for malignant glioma. Luciferase expression was detected by bioluminescence imaging, and the effect of the immunosuppressive agent cyclophosphamide (CPA) on transgene expression was assessed. Intratumoral AdA24CMV-Luc injection led to a localized dose-dependent expression of luciferase. Surprisingly, this expression decreased rapidly during the course of 14 days. In contrast, mice injected with nonreplicating Ad.CMV-Luc demonstrated stable transgene expression. Treatment of mice with CPA in combination with AdA24CMV-Luc retarded the loss of transgene expression. Staining of mouse brains for inflammatory cells demonstrated decreased tumor infiltration by immune cells in CPA-treated mice. Moreover, in immunodeficient NOD/SCID mice loss of transgene expression was less rapid and not prevented by CPA treatment. Together, our data demonstrate that transgene expression and viral replication decrease rapidly after intratumoral injection of oncolytic adenovirus in mouse brains and that treatment with the immunomodulator CPA prolongs viral-mediated gene expression.